On Sat, Jun 6, 2015 at 6:23 PM, Jordan Harband <ljh...@gmail.com> wrote: > if `class SubThing extends Thing {}`, then `new SubThing instanceof Thing` > would be true.
Ah! Good. I expected it to fail just like this: ```js function Thing(){} function SubThing(){} SubThing.prototype = Object.create(Thing) SubThing.prototype.constructor = Thing Object(new SubThing) instanceof Thing // false ``` > Based on your isA examples, `Object(foo) instanceof bar` should be reliable > within a single realm, and works everywhere, without the need for a new > builtin method. I can't think of a way to make something work across realms, so that's indeed the best we have got. _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss